Coffee machine



FIG. 1 is a perspective view of a coffee machine showing our new design;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a left view thereof;

FIG. 5 is a right view thereof;

FIG. 6 is a front view thereof; and,

FIG. 7 is a rear view thereof. 

The ornamental design for a coffee machine, as shown and described. 